In any precision machining operation, precise alignment to and measurement of a work piece, such as a pipe, is crucial to performing a quality machining operation. Regardless of how precise and accurate the movement and control of the machine is, if one cannot accurately place the orientation of the machine to the work piece, the job cannot be performed correctly. This is especially true for field counter boring of pipelines using portable equipment that is designed to operate in a wide variety of working conditions (e.g. on a desert gravel bed, in a sea container on an oil platform, in a pipe yard, etc.). Usually, such portable equipment is machining the inner diameter (“ID”) bore on only a small area of the pipe, thereby making the portable equipment even more sensitive to improper alignment.
One conventional type of measuring and alignment system includes measuring and aligning the machine to a pipe end using a dial indicator (analog or digital). In general, a dial indicator is temporarily mounted to the boring bar of the machine by an operator such that the dial indicator contacts the outer diameter (“OD”) of the pipe end. The operator then rotates the dial indicator around the pipe end in multiple planes. As the operator is rotating the dial indicator, the operator must be able to read and record displacement output from the dial indicator.
The operator then uses a calculator or spreadsheet to determine what movements to the pipe and/or the machine are needed such that the dial indicator no longer moves when the operator is rotating the dial indicator around the pipe. This is an iterative process that can take several rounds of measurements before the operator can achieve the desired alignment of the machine to the pipe end. First, every time the operator moves the pipe or the machine there are new process variables that must be accounted for. For instance, the operator may be setting up the machine on gravel where the elevation can change from one position to the next. Second, the operator must account for two different modes that affect one another. One, the operator must get the portable machining system on center with the pipe end. Two, the operator must get the axis of the portable machining system parallel to the axis of the pipe end.
Typically, the operator first tries to get as close to parallel as possible with the dial indicator. Then, the operator addresses the X, Y, on center position of the portable machining system. A highly skilled operator may be able to sweep for parallelism, adjust the X, Y position of the portable machining system, and then perform one more sweep with the dial indicator for parallelism. An operator who is not as experienced will have to jump back and forth between the two modes two or three times before they are able to get both modes right.
Conventional measuring and alignment systems and methods such as these tend to suffer from a number of drawbacks. For instance, such systems and methods can be very labor intensive and require extensive and specialized operator training. In addition, such systems and methods are prone to operator error and can be inconsistent from one operator or dial indicator to another. Moreover, the cycle times of such systems and methods to align a machining system to a pipe end are generally very long. Further, dial indicators typically have limited accuracy limits and measurement ranges.
In view of the shortcomings of conventional systems and methods, there exists a substantial need for a system and a method to align a machining system to a work piece that is more consistent, faster, less labor intensive, and provides higher accuracy.